Dissertation: Dispersal and habitat quality drive saproxylic fungal communities
What did you research?
In my thesis I studied how dispersal along with environmental factors shape saproxylic fungal communities. For this, I conducted an experiment using pine and spruce logs placed in both mainland and islands of different sizes to understand what shapes communities of saproxylic fungi—organisms that live in the wood and bark of decaying logs.
What is the main result of your research?
The study found that three main factors affect how these fungi colonise new areas: dispersal (how they move from place to place), abiotic filtering (how environmental conditions select which species survive), and stochastic (random) processes. These factors matter at different stages. Saproxylic fungi often struggle to reach more isolated sites, like islands far away from the mainland, because the movement of their spores is limited; however, they can reach these places when carried by the wind. We also found that fungal species were fairly similar within the same log but varied more along the trunk height and between tree species. The dispersal of these fungi is mainly affected by how connected a site is to others, while their ability to deposit and establish in the logs depends more on habitat quality, such as tree species. Finally, by moving logs from isolated sites to more connected sites, we found that random events may prevent these fungal communities from fully recovering even when conditions improve.
How can the results be applied?
These results highlight the importance of connectivity for saproxylic fungal communities. This is important, as globally more than half of forests are fragmented, and in Finland even protected areas have experienced increased loss of connectivity and habitat degradation. The results of my thesis suggest that fungal communities in dead logs may struggle to access isolated forest patches. Therefore, to protect these species when establishing protected areas, it would be important to focus on connecting isolated forest patches, like protecting forests near each other or near high-quality forest (e.g. old forests).
M.Sc. Domenica Naranjo Orrico defends their doctoral dissertation "Influence of connectivity in shaping saproxylic fungal community dynamics” on 4.9.2026 at 12:00 in the lecture hall YAA303 in Ylistönrinne. Opponent is Associate Professor Kadri Runnel (University of Tartu) and custos is Associate Professor Nerea Abrego Antia (University of Jyväskylä). The language of the event is English.
The dissertation "Influence of connectivity in shaping saproxylic fungal community dynamics” is available in the JYX publication archive: https://jyx.jyu.fi/jyx/Record/jyx_123456789_112908?sid=626442349
